I told you over a year ago, that zircons are likely the only item you may have in your radiometric arsenal. We agreed on that. Now, how those billions of years elapsed?
The RATE team found a discrepancy in the lead content and the helium content of the crystals. That discrepancy is real and should not be taken lightly by either side.
[Edit addition: leave sedimentary rock and fossils out of the zircon discussion. They are not related.]
We did not.
Now I’m confused. You seem now to be saying that the zircons are not billions of years old. Which is correct? Are they or aren’t they?
I don’t think you are really confused. You well-know about the claim of accelerated aging. Too, you also know my disagreement with YECs about when it may have happened. In time, I believe they will have no choice in the matter but to ultimately agree with those of us who claim the only possible, scientifically feasible, occurrence of any such event would have been at the top of creation Day 1, not Day 4 as they currently hold to. It will take time to convince them, but I may already see signs that some are starting to “come around”.
And that would explain why you see native zircons in basement rock.
That is a tacit admission that the science doesn’t support a young Earth. If you have to change the observed laws and constants of the universe in order to get the results you want then you don’t have an argument. You aren’t interpreting the same evidence, you are inventing it.
Sorry, it’s hard to keep track of which creationists are into which notions. But if there’s accelerated aging, the zircons aren’t really billions of years old; they’ve just been made to look that way for reasons that seem entirely senseless. They’re really 6000 years old, right?
How do you know they’re native zircons?
You are glossing over what I just said above. Both sides of the argument should take the zircon discrepancy in lead/helium seriously. You are not doing legitimate science otherwise.
I’m busy. We are going in circles.
If only you would take the evidence seriously. You haven’t thus far.
Let’s start with the observation that helium diffusion rates in zircons can change with both ambient temperature and pressure. Do you agree?
Well, you are. Though mostly you’re just refusing to look at data or answer questions.
I am busy but I must address this. You are correct because you would never agree to this. I simply misspoke. What I should have said is that we basically agreed to an impasse in the conversation.
We disagreed on the reason for the impasse, however. I’d say it’s all about you refusing to think about evidence and refusing to answer questions, and when you do answer, being inconsistent.
Incidentally, I think your definition of “intruded” must be different from the one commonly used in geology.
Ah, yes. I think many of us are quite well aware of this. As well as the attendant problems that the more honest creationists admit cannot be overlooked:
As has been shown already in Appendix A.5, the existence of the Po
radiohalos in these granitic rocks, especially the 218Po and 214Po radiohalos
because of the extremely short half-lives of these isotopes, has a direct
implication as to the timescale for cooling of these granitic plutons. The
survival of the Po isotopes and formation of these Po radiohalos places
a severe timescale limit of six to ten days on the cooling of granitic
plutons from 400°C or more down to the ambient temperatures at the
near-surface crustal levels at which these plutons have been emplaced.
This results in the problem of removing the enormous quantity of heat
involved from the huge volume (specifically of the order of 200–500 km3)
of each granitic pluton within six to ten days. Such removal requires
heat dissipation at least six orders of magnitude greater than currently
postulated by conventional wisdom [Petford et al., 2000]. However,
the existence of the Po and 238U radiohalos together, if generated
concurrently, implies nuclear decay had to have been accelerated, by
probably at least six orders of magnitude during the Flood year. The
enormous amount of heat generated by this accelerated nuclear decay
Radiohalos in Granites: Evidence for Accelerated Nuclear Decay 183
adds considerably to the heat problem.To put this heat problem in perspective we can quickly do a rough
estimate of the effect of just the accelerated nuclear decay, say 500
million years worth (at today’s rates), but instead taking place in a single
year (the Flood year). The following values of the relevant parameters
were obtained from Stacey [1992]:
• the typical heat production in a granitic pluton from radioactive decay
of U, Th, and K is ~10-9 W/kg,
• the specific heat of granite is ~700 J/kg-K, and
• the number of seconds in 500 million years is ~1.6 x 1016 sec.
Thus the adiabatic temperature rise =
This is equivalent to a temperature rise of more than 22,000°C, which
is sufficient, of course, to vaporize a granitic pluton many times over!
And, sorry, but you expect intelligent people to actually take this nonsense seriously?
Contingent on prior permissive substitutions that is often the case, yes. It’s a pretty well established result in protein biophysics that, in general, prior replacements elsewhere in a protein can open up for additional near-neutral substitutions. It’s important to understand that you can have divergence and convergence occurring in parallel spread across all positions in a single protein. You can have (say) 20 out of 300 amino acids that have diverged, turn around and converge in lineages separated over vast spans of time under some similar selective constraint, while the remaining 280 amino acids(inherited as identical from a common ancestor) increasingly diverge.
i hope that i got your point correctly (because of my english) but i guess that your answer is in general “yes”. now, if this is true we should not find a protein which only the minority of its amino acids can be replaced with other amino acids. do you agree with that prediction?
No, I did use the term “in general”. While the phenomenon is general, there are exceptions where some proteins have evolved to be under significant purifying selection where they have remained essentially unaltered for hundreds of millions of years.
It also has to be said that, even for those proteins that have remained unaltered for very long periods of time, you actually can replace amino acids in them without destroying the protein’s function, they just have lower fitness, which explains why they are selected against. I think such proteins are likely to have reached some sort of local optimum on significant parts of their sequence.
Again, I have not, nor will I, assert accelerated aging during the Flood.
Note to all here Please cease using this argument against those present. It is irrelevant and leads to long, unnecessary posts like this one from @Faizal_Ali.
Yeah, sure, I can understand why you would prefer us not to quote any of the many, many statements from your fellow creationists that reveal the utter inanity of your belief system.
Not my problem. No one here is obliged to suppress facts that make you look bad.
Oh, now, don’t be mean. @r_speir is taking the evidence very, very seriously. Why, look at what he wrote just a few posts earlier:
Isn’t that just so, so serious? It certainly is not a joke, no sirree.
but remember again what theobald said: “The phenomenon of protein functional redundancy is very general, and is observed in all known proteins and genes”.
so i think that we can both agree that he was wrong about that statment.
Heh, no. The fact that some protein is constrained by purifying selection doesn’t mean many other sequences can’t do it’s job just as well, it just means that in the immediate sequence neighborhood of the conserved sequence, such alternatives aren’t found. And so, to get to those other sequences by small steps would require going through intermediates with significantly lower fitness.
